Everyone has heard about Internet. But what exactly is it and how does it work? How can we use the Internet?
These are questions which I shall try to answer. What I will say is very simplified and I can't tell you all the possibilities of the Internet.
But first it is necessary to understand why the Internet was created:
It was a revolution when everybody could own a PC – a personal computer. Today the Internet is going to revolutionize the data exchange. The future ofthe informatic does not belong to isolated PCs, but to the PC in the Net.
The Internet is a product of the cold war. The American army created it as a secure data net. 1972, two years after, about 40 Universities were connected with the Internet and developed it further.
In the nineties private people could use the Internet services because they were simplified. We can't say how many users the Internet counts, but there are approximately 30 to 60 million people. And this number grows very fast.
The Internet is a world wide net of computers which can exchange data over lines. It is decentrally organised and every computer – PCs, Macs, and so on – can be linked to it.
But where are these computers which are called 'servers'? Where is the Internet? Servers are big computers containing the data of the Internet and are turned on 24 hours a day. You find them all over the world, but they are all linked per lines. So, it is really a big net. Many servers were created by providers. These are people who provide the Internet. They give you the possibility to explore or surf the Internet, to use other services and to present your own pages.
The Internet doesn't offer surfing only. There are a lot of other services which you can use. Following are the most important services:
With E-Mail you can send your letters and documents to other E-Mail-Users. You can be an E-Mail-User if you have an e-mail-address. This is available through your provider.
These addresses look like this: name@provider.ch. First is the user-name or a short form of the name. Then there is the American sign for 'at' (@), following by the server-name. Mostly the address ends with a point and the country.
How does sending and receiving E-Mails work? An example: Suppose I want to send an E-Mail to my sister: First, I write the letter, then I type her e-mail-address and click the button 'send'. I can do this with a program like Eudora, or others. Those E-Mail-programs send the letter to my server; in my case 'DataComm'. Now, my server searches my sister's server and send the mail to hers. The mail is saved by her server. The whole procedure takes only some minutes.
When she wants to receive mail she starts her computer and looks for new mail on her server, like in a mailbox. Because there is something in the mailbox, it sends the e-mail to her and she can read what I have written.
The news is like a board where you can put small letters and questions. Every user can see this 'news' and can answer it. So this can end in a big discussion.
There are a lot of such boards called newsgroups. They all have their own topic. So, there exists a group for market, for programmers, for music, and so on. The language of most of the newsgroups is English.
This is very useful to exchange data, for example programs.
With telnet you can use programs which are on other computers. For many libraries such as the one of the ETH Zurich, you use telnet.
This is the service you use most. It's exciting to surf the Internet, from page to page. You surf with a program called explorer. You have to type the address of the page you want to go to. Such an address looks like http://www.stradax.net. The explorer will look for this page and show it.
On a homepage the firm or the person write who they are and what they do, what they offer. Such a page contains links to other pages which will show the linked page after clicking them.
On many pages you can buy things, from food over textiles to computers. Mostly you pay them with credit cards.
You can imagine that there is an enormous number of pages. You find information also about science, computers, education, business, etc.. Unfortunately also criminals exist in the Internet.
How can you find information on something? You see, you have to type an address if you want that. For this, the most important things are the Search-Engines, like AltaVista, Yahoo, Sear.ch and Webcrawler. These have indexed millions of pages, so you can easily search something you want.
There are also problems with the Internet. E.g. the security. The e-mails you send can be read by any good hacker. So you shouldn't send very private stuff. If you want to pay a program or something by credit cards, you have to send them your credit card number, etc.. Hackers can also get these numbers and use them for their own purpose. Although there exist cryptography-programs, the Internet isn't secure.
Certainly the cost is considerable. You have to pay the telephone and the provider cost per hour. So, it's a good idea to surf during the night, when the telephone cost is deep, except if you are to prepare a speech on Internet on the next day...
There is also a problem with the control. Providers can easily watch what you do on the Internet. Sooner or later, the control will be perfect and total: "Big brother is watching you".
Welcome in the world of Internet! This information net is a revolution similar to the one of Gutenberg. We can tell our grandchildren that we had this great experience at first hand, live! What a good feeling!